Non-restricting conductor filtering system for a hi gh-voltage circuit-breaker

ABSTRACT

A non-restricting conductor filtering system is provided in the high-pressure barriered area of a high-voltage compressed-gas circuit interrupter to prevent damage to the barrier in the event of blast-valve failure, and a consequent differential-pressure drop across the barrier. The filtering system not only permits a ready equalization of the pressure across the barrier, in the event of blast-valve failure, but the filtering prevents any small metallic particles from the contact region from entering into the annular highpressure space between the high-voltage conductor and the surrounding barrier member during subsequent repressurization of the high-voltage, high-pressure area portion of the circuitbreaker.

United States Patent n 1 Bertolino et al.

[ Dec. 3, 1974 NON-RESTRICTING CONDUCTOR FILTERING FOR VOLTAGE CIRCUIT-BREAKER Inventors: August U. Bertolino, Jeannette; Joseph A. Penkova; William G.

Carrell, both of Pittsburgh, all of Pa.

Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

Filed: Sept. 13, 1972 Appl. No.2 288,843

US. Cl 200/148 B, 200/148 E Int. Cl. H0lh 33/54 Field of Search ;200/-148 R, 148 B, 148 E,

References Cited UNITED STATES PATENTS 8/1972 Kane et al. 200/148 B Primary Examiner-Robert S. Macon Attorney, Agent, or Firm-W. R. Crout 5 7 ABSTRACT A non-restricting conductor filtering system is provided in the high-pressure barriered area of a highvoltage compressed-gas circuit interrupter to prevent damage to the barrier in the event of blast-valve failure, and a consequent differential-pressure drop across the barrier.

The filtering system not only permits a ready equalization of the pressure across the barrier, in the event of blast-valve failure, but the filtering'prevents any small metallic particles from the contact region from entering into the annular high-pressure space between the high-voltage conductor and the surrounding barrier member during subsequent repressurization of v the high-voltage, high-pressure area portion of the circuit-breaker.

17, Claims, 11 Drawing Figures HIGH PRESSURE FOR EXAMPLE ZOO-240 PSI.

PATENTELBEE 31914 I sum 10F 6 INSULATION PATNTELUEB alas-2.550

sum 30F a PRESSURE FOR EXAMPLE 200-240 PSI.

INSULATION PATENTEL DEB SHEET -5 0F 6 FIG. IO

CROSS-REFERENCE TO RELATED APPLICATIONS Reference may be made to U.S. Pat. application filed Mar. 9, I971, Ser. No. 122,453, by Cookson et al., also see Cookson et al., Ser. No. 384,653, filed Aug. 1, 1973, both applications being assigned to the assignee of the instant application. Also, reference may be made to U.S. Pat. application W.E. 42,010, filed Nov. l4,

1972, Ser. No. 306,493, by Cookson et al., and likewise 4 assigned to the assignee of the instant application.

BACKGROUND OF THE INVENTION sulating barriers to prevent a-free space existing between the inner high-voltage conductor and the surrounding outer grounded housing. 1

To prevent metallic particles from entering the region between the inner high-voltage conductor and the intermediately disposed barrier, it was arranged to somewhat seal the ends of the tubular barrier to the I inner high-voltage conductor.

SUMMARY OF THE INVENTION In accordance with the present invention, to prevent a bur sting of the tubular barrier in the event of blast- I valve failure, a free venting system has been provided between the annular high-pressure region immediately surrounding the high-voltage conductor, into the tubular high-voltage conductor, and to the region surrounding the contact area. To prevent, however, the entrance of small metallic particles into the inner annular region betweenthe barrier and the inner high-voltage conductor, during repressurization of the high-pressure; system, it has been proposed to incorporate a filtering sys: tem into such venting, so that the metallic particles will be prevented from entering the annular space between the barrier and the innerIhigh-voltage conductor. As a result, a clean annular space is provided between the inner high-voltage conductor and the intermediatelypositioned tubular insulating barrier. T

Accordingly, it is a general object of the'present invention to provide an improved high-pressure system associated with a high-voltage compresseds circuit interrupter. 0

Another object of the present invention is the provision of an improved barrier system having the internal region thereof freely vented to prevent bursting thereof during blast-valve failure.

Another object of the present invention is the prev vention of a pressure drop across a barrier in the event of blast-valve failure, and a sudden drop of pressure outside of the barrier.

nally of the barrier member, so that a differential pressure drop across the barrier will'be prevented, and, ad ditionally, the filtering will prevent the entrance of any small metallic contaminants into the high-pressure system within the barrier member during a subsequent repressurization of the high-pressure system.

Further objects and advantages will readily become I apparent upon reading the following specification,

taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partially in vertical section, taken through a high-voltage compressed-gas circuit-breaker incorporating the principles of the present invention;

FIG. 2 is a sectional view taken substantially along the line IIII of FIG. 1;

. FIG. 3 is 'a fragmentary side-elevational view of a portion of the high-voltage and high-pressure system;

FIG. 4 is a detailed sectional view of a portion of the high-pressure system of a modified type of two-break circuit breaker, more clearly illustrating the disposition of the interrnediately situated tubular barrier, relevant to the inner high-voltage conductor, and showing the location of the filtered vents but accomodating two series arc-extinguishing assemblages;

FIG. 5 is a fragmentary sectional view illustrating the location andarrangement of the cylindrical filters disposed in diametrically opposite vents provided in the walls of the high-voltage inner tubular conductor;

FIG. 6 is an enlarged sectional view taken along the lineVl-Vl of FIG. 5;

FIG. 7 is a detailed sectional view of the filter itself;

' DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more. particularly to FIGS. 1 and 2 thereof, the reference numeral 1 designates a high-voltage compressed-gas circuitinterrupter. This type of circuit-breaker 1 has been fully described in the following U.S. Pat. Nos.: 3,590,189 Fischer et al.; 3,639,713 Fischer et al.; 3,665,133 Reese et al.; 3,624,329 Fischer et al.; 3,603,754 Reese et al.; and 3,596,028 Kane et al.

Generally, it will be noted that the interrupter section 2 is disposed to the right as viewed in FIG. 1, and the bushing section 3 is located to the left, as illustrated in FIG. 1. Reference may be made to FIGS. 18-20 of U.S. Pat. No. 3,596,028 for a description of how the interrupter and bushing sections maybe varied to accommodate various voltage and current ratings of the interrupter. I

As set forth in more detail in Us. Pat. No. 3,596,028,

it will be noted that there is provided a high-pressure region 22, 24, disposed at the lower end of the inter rupter, and comprising, generally, an outer metallic tubular grounded housing, designated by the reference numeral 5, as illustrated in FIG. 3, together with an internal concentrically arranged tubular high-voltage conductor, designated by the reference numeral 6 in FIG. 2.

Insulation 8 may be provided around the grounded v conductor 5, together with one or more heaters 10 (FIG. 1) to prevent liquefaction of the internally provided gas 12, which may, for example, be sulfurhexafluoride SP gas.

As set forth in the aforesaid patents, during normal operation, a primary blast-valve 11 opens and gas passes between the tubular contacts 14, 16, and through them in a manner described in U.S Pat. No. 3,665,133.

In more detail, the movable sleeve contact 14 moves upwardly, during the opening operation, separating from a relatively stationary blast-valve seat 18, and permitting high-pressure gas within the region 20 to pass radially inwardly and upwardly through the region- 19 interiorly of the movable sleeve contact 14 and also downwardly intothe region 17 within the relatively stationary contact 16. This radially inward flowing blast of high-pressure gas 12, from the region into the regions 17, 19 exhausts into enhaust chambers, designated by the reference numerals 26 and 28, and continues until the secondary blast valves 29 close tohalt the continued blasting of gas through the interior of the tubular contacts l4, 16. At this time, the arc (not shown) is extinguished. The exhaust chambers 26 and 28 are pneumatically interconnected byan insulating cylinder 7 33, throughuwhich' passes a valve-control rod 34, which is actuated by an operating mechanism at ground potential, and constituting no part of the present-inven- 1 eration, the primary blast-valve 11 opens, as men' tioned, permitting high-pressure gas to flow radially inwardly, and upwardly and downwardly through the movable tubular and relatively stationary contacts 14,

16, respectively, until arc extinction ensues, and, subsequently, the secondary blast-valves 29 are closed mechanicallyfThus, in the fully open-circuit position of the interrupter of FIG. 10, the contacts l4, 16 are separated, the primary blast-valve 11 is open, the secondary blast valve's29 are closed, and high-pressure gas exists throughout the region '15 and the two regions 17 and 19 interiorly of the separated'contacts 14, 16. v

Supporting the arc-extinguishing assemblage 36 within the casing structure 33 is a truncated insulating cone-shaped member 40, supported by bolts 42 to. a grounded heavy ring-shaped flange member 44, which in turn, is affixed to the lower heavy U-shaped casting members, illustrated more clearly in FIG. 3 of the drawings. As shown, the high-voltage conductor 6 passes centrally through. the'ihsulating cone-shaped member 40, and is separablyconnected to spring fingers 46, constituting the lower assembly of the lower exhaust chamber 28, as shown more clearly in FIG. 10'

of the drawings.

The movable tubular contact 14 is actuated upwardly by a pair of rod-shaped insulating members 48, actuated by a pneumatic piston structure disposed in the head portion 50 (FIG; 1) of the interrupting assemblage 2. The pair of rod-shaped members 48have inwardly extending arm portions 52, which first tension compression springs 54 to tend to effect theclosing of the secondary blast-valves 29, as illustrated in FIG. 10. However, the secondary blast-valves29 are latched open, in the manner shown in FIG. 10, by latching members 56 disposed on opposite sides of the casting member 58, and pivotally mounted at 60. After a predetermined opening operation, the upward movement of the arms 52 cams the latching members 56 outwardly, and releases the secondary blast-valve 29 permitting the latter to. close under, the impetus of the compression springs 54. This latching and control of the secondary blast-valves 29 is more clearly set forth in U.S. Pat. 3,665,133, issuedMay 23, I972 to Reese ration. I

It will be noted, with reference to FIGS. 2 and 10, that should the primary blast-valve 11 for any reason remain stuck open, there would result a rapid drop of pressure on the] outside 24 of the :barrier 20 and through the venting contacts l4, 16. Previously, the tubular insulating barrier 20 was generally somewhat sealed to the upper ends of the high-voltage conductor 6, as illustrated in FIG. 4; As-will be obvious-, this inner annular space 22, at high pressure, would'notdrop in pressure as rapidlyas the outer space, designated by the reference numeral-24 in FIG. 2, which has much more free communication with the interrupter space. Breakage of barrier 20 was a hazard. I

We have. discovered that byproperly.adequately venting the inner high-voltage conductor 6, the pressurewill drop within the barrier 20 in annular space 22 as rapidly .as it drops on the outside thereof in region 24, and, consequently, there will occur no net differential pressure drop acrossnthe insulating barrier 20. The upper ends of the innerhigh-voltage conductor 6 are, of course, vented as at 6a to the interrupting space 15, as illustrated. in FIG.19.

As shown moreclearly in FIGS. 5 and 6, a cylindrical filter 30 is disposedwithinthe diametrically oppositely arranged openings. 32. provided in the .inner highvoltage. conductor, and a pair of nuts 35 and 37 are torqued into position. Adhesive may be utilized in conjunction with the nuts 35, 37 to assure that once they are torqued into place, they will not subsequently o a FIGS. 7 and 8 show detail views of the cylindrical fil ter 30. It will be observed that thefilter 30 is of mesh construction, andis secured to a pair of opposite end supporterrings 41, which may be placed into position within the inner high-voltage conductor 6 prior to the insertion of the nuts 35, 37 there'into'.

I that should the secondary blast valves 29 remain, for,

From the foregoing'description, it will be apparent any reason, stuckfin the open position, this would effect a rapid reductionwithin' the outer, high-pressure third region 24 with respect to the high-presure second reet al. and assigned 'to the Westinghouse Electric Corpoand to the slow leakage'inside the barrier member 20,

there would result the hazard that the barrier member 20 would fracture, or otherwise suffer damage. By rapidly venting the inner high-pressure region 22 through thevents 30 into the interior 62 of a'first high-pressure region with the tubular high-voltage conductor 6, as il- 'lustratedin FIGS. 4 and 11, there will result an equalization of pressure between the second and third regions 22, 24, and no resultant differential pressure will be caused to occur across the insulating barrier mem- 7 bar 20. It will be observed, with respect to FIG. 4, that high-voltage conductor 6 and upwardly through the vent openings 6a, as illustrated at the upper end of FIG. 4 of the drawings. 1 a V The following requirements are desirable for thefiltering system by way ofexample:

l. Filtration: 40 micron nominal Servicez sF gas 1 I Flow rate: l2.SCFM at,40 PSlG- Max AP (clean): 1.0 PSID at -ratedflow Temp. Range: to 175F v .Media: Micrweave 304L Wire mesh Assemble with silver braze Element will withstand 40 P816 internal pressure without rupture.

The provision of the filter 30 prevents the entrance of small metallic particles and contaminants into the inner barrier. region 22 during the subsequent repressurization of the high-pressure system, should'blastvalve failure occur, or, during a normal maintenance operation, when it is desired to repressurize the system.

From the foregoing description, it will be apparent that we have provided an improved venting arrangement, whereby a differential pressure drop will not occur across the cylindrical insulating barrier 20 during a possible'blast-valve failure. In addition, we have illustrated the use of a filtering system to prevent the entrance of small metallic particles into the high-pressure seond region internally of the cylindrical insulating barrier 20 within annular region .22.

Theuse of the insulating tubular barrier is set forth in U.S. Pat. application'fil'ed Aug. 1, i973, Ser. No.

384,526,- by Cookson et al. and assigned to the assignee of the instant application.

6. disposed within said high-pressure interrupting region (15);

c. relatively low-pressure exhausting means (26) pneumatically connected with said one tubular contact (14) to receive an exhausting blast of highpressure gas from said high-pressure interrupting region (15) during the arc-interruption process;

(1. a hollow metallic high-voltage line-conductor (6) constituting a first high-pressure storage region electrically connected to one of said separable contacts and freely vented to-said high-pressure interrupting region (15); e. a hollow insulating barrier member (20) surrounding said high-voltage metallic line-conductor (6) and defining an annular sealed second highpressure region (22); f. means defining a third outer high-pressure region (24) freely communicating pneumatically with said high-pressure interrupting region (15) and disposed about said barrier member (20); and,

g. means defining equalization opening means (32) provided in the wall of said inner hollow metallic high-voltage line-conductor (6) which pneumatically interdommunicates the interior (62) ofthe high-voltagem etallic line-conductor (6) with the annular region (22) within. the barrier member. (22), whereby a sudden drop of pressure within the outer high-pressure region (24) will not fracture the barrier member (20) because of the permissible rapid equalization of pressure across the barrier member- (20) provided by said equalization opening means (32). i 2. The high voltage high-power compressed-gas circult-interrupter of .claim 1, wherein filtering means U-shaped barrier member (20).

5. The combination according to claim '1, wherein the means defining the-outer third high-pressure region (24) includes a generally U-shaped grounded hollow metallic member. I I 6. The combination according to claim l, wherein secondary blast-valve means controls the exhausting flow from the high-pressure interrupting region (15) throughsaid one tubular contact and into the lowpressure exhausting means (26).

7.The combination according to claim 1, wherein the equalization opening means comprises a plurality of spaced venting passages (32) leading into the interior of the high-voltage metallic line-conductor (6) from theouter annular high-pressure second storage region 8, The combination according to claim 2*,wherein the filtering means comprises one or more tubular cartridge elernents (30) having wire screening associated therewith to filter out the particles. t

9. The combinationaccording'to claim 1, wherein one or more spacer elements (65) are provided along the length of the hollow metallic high-voltage lineconductor ('6) to space the barrier member (20) outwardly from the inner-disposed high-voltage lineconductor (6).

10. A high-voltage high-power compressed-gas circuit-interrupter, comprising, in combination:

a. means defining a high-pressure interrupting region b. a pair of cooperable separable contacts (14, 16)

disposed within said high-pressure interrupting region (15); I

c. means defining a relatively high-pressure first region 62 pneumatically communicating with said high-pressure interrupting region (15);

d. means defining a secondary high-pressure gasstorage region (22) in juxtaposition to said firstmentioned first high-pressure storage region (62) and having an insulating wall portion associated therewith;

e. means defining a third high pressure storage region (24) freely pneumatically communicating with'said high-pressure interrupting region (15); and,

f. means defining equalization opening means (32) provided in the wall of the first-mentioned, first high-pressure storage region (62) which pneumatically intercommunicates the first high-pressure storage region (62) with the second. high-pressure storage region (22), whereby a sudden drop of pressure within the thirdhigh-pressure storage rev cause of the permissible rapid equalization of pressure across said wall member (20) provided by said equalization opening means (32). g 11. The combination of claim 10, wherein'filtering means(30) is provided within the equalization opening means (32) to filter out any small particles from enteringthe second high-pressure storage region (22).

12. The combination according to claim 10, wherein one of the cooperable separable contacts is tubular and vents the high-pressure gas away from the arcing region (15).

13. The combination accordingvto claim 10, wherein the first-mentioned highmressure storage region 62) is constituted by a generally hollow metallic line conductor (6).

14. The combination according to claim 13, wherein the second high-pressure storage region (22) is constituted by a generally surrounding insulating tubular member (20) in spaced relationship to the inner disposed tubular member (6).

15. The combination according to claim 10, wherein the third region (24) is at least in part defined by an outer hollow member (5). I I 16. Thecombination according to claim 15, wherein the outer member 5 is a'metallic grounded tubular member. a v

17.,The combination according to claim 16, wherein the outertubular member is generall'ytU-shapedin configuration. 

1. A high-voltage high-power compressed-gas circuit interrupter, comprising, in combination: a. means defining a high-pressure interrupting region (15); b. a pair of cooperable separable contacts (14, 16) at least one of which (14) is tubular and both contacts disposed within said high-pressure interrupting region (15); c. relatively low-pressure exhausting means (26) pneumatically connected with said one tubular contact (14) to receive an exhausting blast of high-pressure gas from said high-pressure interrupting region (15) during the arc-interruption process; d. a hollow metallic high-voltage line-conductor (6) constituting a first high-pressure storage region electrically connected to one of said separable contacts and freely vented to said high-pressure interrupting region (15); e. a hollow insulating barrier member (20) surrounding said high-voltage metallic line-conductor (6) and defining an annular sealed second high-pressure region (22); f. means defining a third outer high-pressure region (24) freely communicating pneumatically with said high-pressure interrupting region (15) and disposed about said barrier member (20); and, g. means defining equalization opening means (32) provided in the wall of said inner hollow metallic high-voltage lineconductor (6) which pneumatically intercommunicates the interior (62) of the high-voltage metallic line-conductor (6) with the annular region (22) within the barrier member (22), whereby a sudden drop of pressure within the outer highpressure region (24) will not fracture the barrier member (20) because of the permissible rapid equalization of pressure across the barrier member (20) provided by said equalization opening means (32).
 2. The high-voltage high-power compressed-gas circuit-interrupter of claim 1, wherein filtering means (30) is provided within the equalization opening means (32) to filter out any small particles from entering the annular second high-pressure region (22) within the barrier member (20).
 3. The combination according to claim 1, wherein both of the cooperable separable contacts are tubular and constitute venting contacts.
 4. The combination according to claim 1, wherein the hollow metallic high-voltage line-conductor (6) is generally U-shaped and is disposed within a generally U-shaped barrier member (20).
 5. The combination according to claim 1, wherein the means defining the outer third high-pressure region (24) includes a generally U-shaped grounded hollow metallic member.
 6. The combination according to claim 1, wherein secondary blast-valve means controls the exhausting flow from the high-pressure interrupting region (15) through said one tubular contact and into the low-pressure exhausting means (26).
 7. The combination according to claim 1, wherein the equalization opening means comprises a plurality of spaced venting passages (32) leading into the interior of the high-voltage metallic line-conductor (6) from the outer annular high-pressure second storage region (22).
 8. The combination according to claim 2, wherein the filtering means comprises one or more tubular cartridge elements (30) having wire screening associated therewith to filter out the particles.
 9. The combination according to claim 1, wherein one or more spacer elements (65) are provided along the length of the hollow metallic high-voltage line-conductor (6) to space the barrier member (20) outwardly from the inner-disposed high-voltage line-conductor (6).
 10. A high-voltage high-power compressed-gas circuit-interrupter, comprising, in combination: a. means defining a high-pressure interrupting region (15); b. a pair of cooperable separable contacts (14, 16) disposed within said high-pressure interrupting region (15); c. means defining a relatively high-pressure first region 62 pneumatically communicating with said high-pressure interrupting region (15); d. means defining a secondary high-pressure gas-storage region (22) in juxtaposition to said first-mentioned first high-pressure storage region (62) and having an insulating wall portion (20) associated therewith; e. means defining a third high pressure storage region (24) freely pneumatically communicating with said high-pressure interrupting region (15); and, f. means defining equalization opening means (32) provided in the wall of the first-mentioned, first high-pressure storage region (62) which pneumatically intercommunicates the first high-pressure storage region (62) with the second high-pressure storage region (22), whereby a sudden drop of pressure within the third high-pressure storage region (24) will not fracture said wall portion (20) of the second high-pressure storage region (22) because of the permissible rapid equalization of pressure across said wall member (20) provided by said equalization opening means (32).
 11. The combination of claim 10, wherein filtering means (30) is provided within the equalization opening means (32) to filter out any small particles from entering the second high-pressure storage region (22).
 12. The combination according to claim 10, wherein one of the cooperable separable contacts is tubular and vents the high-pressure gas away from the arcing region (15).
 13. The combination according to claim 10, wherein the first-mentioned high-pressure storage region (62) is constituted by a generally hollow metallic line conductor (6).
 14. The combination according to claim 13, wherein the second high-pressure storage region (22) is constituted by a generally surrounding insulating tubular member (20) in spaced relationship to the inner-disposed tubular member (6).
 15. The combination according to claim 10, wherein the third region (24) is at least in part defined by an outer hollow member (5).
 16. The combination according to claim 15, wherein the outer member 5 is a metallic grounded tubular member.
 17. The combination according to claim 16, wherein the outer tubular member is generally U-shaped in configuration. 